Search Publications
Mode visibilities in radial velocity and photometric Sun-as-a-star helioseismic observations
García, R. A.; Ballot, J.; Salabert, D.
We analyze more than 5000 days of high-quality Sun-as-a-star, radial velocity GOLF and photometric VIRGO/SPM helioseismic observations to extract precise estimates of the visibilities of the low-degree p modes and the m-height ratios of the l = 2 and 3 multiplets in the solar acoustic spectrum. The mode visibilities are shown to be larger during t…
Nebular and global properties of the gravitationally lensed galaxy "the 8 o'clock arc"
Schaerer, D.; Dessauges-Zavadsky, M.; Richard, J. +2 more
We present the analysis of new near-infrared, intermediate-resolution spectra of the gravitationally lensed galaxy "the 8 o'clock arc" at zsys = 2.7350 obtained with the X-shooter spectrograph on the Very Large Telescope. These rest-frame optical data, combined with Hubble and Spitzer Space Telescopes images, provide very valuable infor…
Detection of a large massive circumstellar disk around a high-mass young stellar object in the Carina Nebula
Preibisch, T.; Zinnecker, H.; McCaughrean, M. J. +5 more
Context. The characterization of circumstellar disks around young stellar objects can provide important information about the process of star formation and the possible formation of planetary systems.
Aims: We investigate the spatial structure and the spectral energy distribution of a newly discovered edge-on circumstellar disk around an opti…
X-ray observations of sub-mm LABOCA galaxies in the eCDFS
Comastri, A.; Georgantopoulos, I.; Rovilos, E.
We explore the X-ray properties of the 126 sub-mm galaxies (SMGs) of the LABOCA survey in the CDFS and the eCDFS regions. SMGs are believed to experience massive episodes of star formation. Our goal is to examine whether star formation coexists with AGN activity, determine the fraction of highly obscured AGN, and finally to obtain an idea of the d…
Suzaku and SWIFT-BAT observations of a newly discovered Compton-thick AGN
Moretti, A.; Vignali, C.; La Parola, V. +4 more
Context. Obscured AGN are fundamental to understand the history of supermassive black hole growth and their influence on galaxy formation. However, the Compton-thick AGN (NH > 1024 cm-2) population is basically unconstrained, with less than a few dozen confirmed Compton-thick AGN found and studied so far. A way …
The initial conditions of high-mass star formation: radiative transfer models of IRDCs seen in the Herschel Hi-GAL survey
Griffin, M.; Peretto, N.; Ward-Thompson, D. +13 more
The densest infrared dark clouds (IRDCs) may represent the earliest observable stage of high-mass star formation. These clouds are very cold, hence they emit mainly at far-infrared and sub-mm wavelengths. For the first time, Herschel has provided multi-wavelength, spatially resolved observations of cores within IRDCs, which, when combined with rad…
Evidence for a resonant cyclotron line in IGR J16493-4348 from the Swift-BAT hard X-ray survey
Cusumano, G.; Robba, N. R.; La Parola, V. +4 more
Context. Resonant absorption cyclotron features are a key diagnostic tool to directly measure the strength of the magnetic field of accreting neutron stars. However, typical values of cyclotron features lie in the high-energy part of the spectrum between 20 keV and 50 keV, where detection is often damped by the low quality statistics of results de…
Evolution of the fundamental plane of 0.2 < z < 1.2 early-type galaxies in the EGS
Cepa, J.; Bongiovanni, A.; Pérez García, A. M. +5 more
Context. The fundamental plane links the structural properties of early-type galaxies such as its surface brightness and effective radius with its dynamics. The study of the fundamental plane evolution therefore has important implications for models of galaxy formation and evolution.
Aims: This work aims to identify signs of evolution of earl…
Optical and infrared properties of active galactic nuclei in the Lockman Hole
Burwitz, V.; Salvato, M.; Rovilos, E. +4 more
We present the observed-frame optical, near-, and mid-infrared properties of X-ray-selected active galactic nuclei (AGN) in the Lockman Hole. Using a likelihood ratio method on optical, near-infrared or mid-infrared catalogues, we assigned counterparts to 401 out of the 409 X-ray sources of the XMM-Newton catalogue. Accurate photometry was collect…
Modelling solar irradiance variability on time scales from minutes to months
Solanki, S. K.; Krivova, N. A.; Seleznyov, A. D.
We analyze and model total solar irradiance variability on time scales from minutes to months, excluding variations due to p-mode oscillations, using a combination of convective and magnetic components. These include granulation, the magnetic network, faculae and sunspots. Analysis of VIRGO data shows that on periods of a day or longer solar varia…